After some investigation, it turns out the electrical issues I was having *did* originate with this company’s work. It turns out they failed to connect the neutral to anything at all when installing a disconnect, which caused all my lights upstairs to immediately blow out, and none of the outlets to work properly. Thanks for that. When I discussed the problem with another electrician, I was told«I hope this guy was not a real electrician. I shutter to think what other mistakes there are that we cannot see.»